I'm looking to harden my email server and one of the things I want to do is store inbound email on the server in PGP encrypted form. Email arrives via SMTP unencrypted and I want to have it encrypted before it is stored in the Mailbox. The point is to safeguard against email being picked up in the event that someone should breech the security of the server and gain access to files and or gain access to pop3 or imap. The pgp encrypted email would be downloaded by the client and unencrypted by software on the client. Can anyone point me in the right direction for finding such a filter for Postfix?